/*
   _____              _                _____ _
   |  __ \            (_)              / ____| |
   | |__) |__ _ __ ___ _  __ _ _ __   | |    | |__   ___  ___ ___
   |  ___/ _ \ '__/ __| |/ _` | '_ \  | |    | '_ \ / _ \/ __/ __|
   | |  |  __/ |  \__ \ | (_| | | | | | |____| | | |  __/\__ \__ \
   |_|   \___|_|  |___/_|\__,_|_| |_|  \_____|_| |_|\___||___/___/

   Persian Chess v2.0.0 — Full Stylesheet
   CSS Grid, Flexbox, custom properties
*/

/* ═══════════════════════════════════════════════════
   Custom Properties & Reset
   ═══════════════════════════════════════════════════ */
:root {
    --board-light: #f0d9b5;
    --board-dark: #b58863;
    --board-bg: #4a4a4a;
    --frame-color: #333F33;
    --panel-bg: #1c1c1c;
    --panel-text: #d4d4d4;
    --accent: #9ca3af;
    --accent-hover: #c0c6cf;
    --danger: #C0392B;
    --success: #27AE60;
    --highlight-from: rgba(255, 255, 0, 0.4);
    --highlight-to: rgba(255, 255, 0, 0.5);
    --highlight-check: radial-gradient(circle, rgba(255,0,0,0.6) 0%, transparent 70%);
    --highlight-mate: radial-gradient(circle, rgba(255,0,0,0.9) 0%, transparent 70%);
    --selected: rgba(155, 199, 0, 0.45);
    --shadow: 0 2px 8px rgba(0,0,0,0.4);
    --radius: 8px;
    --font-mono: 'Courier New', Courier, monospace;
    --transition: 0.2s ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

button, select, input, textarea { font: inherit; }

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    -ms-touch-action: manipulation;
    touch-action: manipulation;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    font-weight: 600;
    background: var(--board-bg);
    color: var(--panel-text);
    overflow: hidden;
    height: 100dvh;
    width: 100vw;
}

/* ═══════════════════════════════════════════════════
   App Layout
   ═══════════════════════════════════════════════════ */
#app {
    display: flex;
    flex-direction: row;
    height: 100vh;
    width: 100vw;
}

#board-area {
    flex: 1 1 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 1vh;
    position: relative;
    min-width: 0;
    container-type: size;
}

#side-panel {
    flex: 1;
    min-width: 240px;
    max-width: 360px;
    background: var(--panel-bg);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: -2px 0 12px rgba(0,0,0,0.5);
}

/* ═══════════════════════════════════════════════════
    Board — CSS Grid 11×11
    ═══════════════════════════════════════════════════ */
.board {
    display: grid;
    grid-template-columns: repeat(11, 1fr);
    grid-template-rows: repeat(11, 1fr);
    aspect-ratio: 1 / 1;
    touch-action: none;
    /* Largest square that fits inside #board-area. cqw/cqh come from the
       container-type: size on #board-area, so it re-computes on any resize
       without hard-coded side-panel widths. */
    width: min(100cqw, 100cqh);
    height: auto;
    min-height: 0;
    border: 0;
    border-radius: 2px;
    box-shadow: var(--shadow);
    position: relative;
}

.grid-cell {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.grid-cell.off-board {
    background: var(--board-bg);
    cursor: default;
}

.grid-cell.playable {
    cursor: pointer;
}

.grid-cell.light {
    background-color: var(--board-light);
}

.grid-cell.dark {
    background-color: var(--board-dark);
}

.grid-cell.centre-persian {
    background-image: url("../img/persian.png");
    background-size: 100%;
    background-position: center;
    background-repeat: no-repeat;
}

.grid-cell.centre-pyramid {
    background-image: url("../img/pyramid.png");
    background-size: 100%;
    background-position: center;
    background-repeat: no-repeat;
}

.grid-cell.highlight-from {
    background-color: var(--highlight-from) !important;
}

.grid-cell.highlight-to {
    background-color: var(--highlight-to) !important;
}

.grid-cell.selected {
    background-color: var(--selected) !important;
}

.grid-cell.highlight-check {
    background: var(--highlight-check);
}

.grid-cell.highlight-mate {
    background: var(--highlight-mate);
}

.grid-cell::after {
    content: '';
    position: absolute;
    inset: 0;
    transition: background var(--transition);
}

/* Piece elements */
.piece {
    width: 100%;
    height: 100%;
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    position: relative;
    z-index: 1;
    pointer-events: none;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
}

/* ═══════════════════════════════════════════════════
   Board Status Bar
   ═══════════════════════════════════════════════════ */
.grid-cell.off-board[data-status]::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 30%;
    height: 30%;
    transform: translate(-50%, -50%);
    border: 1px solid rgba(0,0,0,0.5);
}

.grid-cell.off-board[data-status="white"]::after { background: #fff; }
.grid-cell.off-board[data-status="black"]::after { background: #000; }
.grid-cell.off-board[data-status="white-wins"]::after { background: #fff; box-shadow: 0 0 6px 2px var(--accent); }
.grid-cell.off-board[data-status="black-wins"]::after { background: #000; box-shadow: 0 0 6px 2px var(--accent); }
.grid-cell.off-board[data-status="paused"]::after { background: transparent; border-color: rgba(255,255,255,0.4); }
.grid-cell.off-board[data-status="thinking"]::after {
    background: transparent;
    border: 2px solid var(--accent);
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin { to { transform: translate(-50%, -50%) rotate(360deg); } }

/* ═══════════════════════════════════════════════════
   Side Panel — Header
   ═══════════════════════════════════════════════════ */
.panel-header {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px;
    background: rgba(0,0,0,0.2);
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

.panel-toggle-btn {
    display: none; /* Hidden on desktop */
    background: none;
    border: none;
    color: var(--panel-text);
    cursor: pointer;
    padding: 4px;
}

.logo {
    width: 32px;
    height: 32px;
    border-radius: 4px;
}

.panel-title {
    flex: 1;
}

.panel-title b {
    font-size: 1rem;
    color: var(--accent);
    display: block;
    line-height: 1.2;
}

.version {
    font-size: 0.7rem;
    opacity: 0.6;
}

/* ═══════════════════════════════════════════════════
   Tabs
   ═══════════════════════════════════════════════════ */
.tab-nav {
    display: flex;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.tab-btn {
    flex: 1;
    padding: 10px 8px;
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    color: var(--panel-text);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition);
}

.tab-btn:hover { background: rgba(255,255,255,0.05); }

.tab-btn.active {
    border-bottom-color: var(--accent);
    color: var(--accent);
    font-weight: 600;
}

.tab-content {
    display: none;
    flex: 1;
    overflow-y: auto;
    padding: 12px;
}

.tab-content.active { display: flex; flex-direction: column; gap: 12px; }

/* ═══════════════════════════════════════════════════
   Game Tab
   ═══════════════════════════════════════════════════ */
.action-bar {
    display: flex;
    gap: 6px;
}

.menu-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
}

.menu-btn {
    flex: 1;
    padding: 0 8px;
    height: 38px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
    background: rgba(156, 163, 175, 0.15);
    border: 1px solid rgba(156, 163, 175, 0.3);
    border-radius: var(--radius);
    color: var(--accent);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition);
}

.menu-btn:hover {
    background: rgba(156, 163, 175, 0.3);
    border-color: var(--accent);
}

.menu-btn:active { transform: scale(0.97); }

.menu-select {
    flex: 1;
    padding: 8px;
    background: rgba(0,0,0,0.3);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius);
    color: var(--panel-text);
    font-size: 0.85rem;
}

.action-btn {
    flex: 1;
    padding: 10px 8px;
    background: rgba(156, 163, 175, 0.15);
    border: 1px solid rgba(156, 163, 175, 0.3);
    border-radius: var(--radius);
    color: var(--accent);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition);
}

.action-btn:hover {
    background: rgba(156, 163, 175, 0.3);
    border-color: var(--accent);
}

.action-btn:active { transform: scale(0.97); }

.move-list {
    flex: 1;
    min-height: 120px;
    max-height: 40vh;
    overflow-y: auto;
    background: rgba(0,0,0,0.2);
    border-radius: var(--radius);
    padding: 8px;
    font-size: 0.85rem;
    line-height: 1.6;
}

.move-list .move-row {
    display: flex;
    gap: 4px;
}

.move-list .move-num {
    color: rgba(255,255,255,0.3);
    min-width: 30px;
    text-align: right;
    margin-right: 8px;
}

.move-list .move-text {
    color: var(--panel-text);
    font-family: var(--font-mono);
}

.console-area {
    margin-top: 12px;
}

.console-textarea {
    width: 100%;
    height: 200px;
    background: rgba(0,0,0,0.3);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius);
    color: var(--panel-text);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    padding: 8px;
    resize: none;
}

/* ═══════════════════════════════════════════════════
   Settings Tab
   ═══════════════════════════════════════════════════ */
.setting-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.setting-label {
    font-size: 0.8rem;
    color: rgba(255,255,255,0.6);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.setting-select,
.form-select {
    width: 100%;
    padding: 8px 10px;
    background: rgba(0,0,0,0.3);
    border: 1px solid rgba(255,255,255,0.15);
    border-radius: var(--radius);
    color: var(--panel-text);
    font-size: 0.9rem;
    cursor: pointer;
}

.setting-select:focus,
.form-select:focus {
    outline: none;
    border-color: var(--accent);
}

.setting-range {
    width: 100%;
    accent-color: var(--accent);
}

.setting-value {
    text-align: right;
    font-size: 0.85rem;
    color: var(--accent);
}

/* ═══════════════════════════════════════════════════
   Moves Tab
   ═══════════════════════════════════════════════════ */
.pgn-viewer {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.pgn-actions {
    display: flex;
    gap: 6px;
}

.pgn-btn {
    flex: 1;
    padding: 8px;
    background: rgba(156, 163, 175, 0.1);
    border: 1px solid rgba(156, 163, 175, 0.25);
    border-radius: var(--radius);
    color: var(--accent);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition);
}

.pgn-btn:hover {
    background: rgba(156, 163, 175, 0.25);
}

.pgn-slot {
    padding: 6px 10px;
    background: rgba(0,0,0,0.3);
    border: 1px solid rgba(255,255,255,0.15);
    border-radius: var(--radius);
    color: var(--panel-text);
    font-size: 0.85rem;
}

.demo-actions {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 8px;
    padding-top: 12px;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.demo-buttons {
    display: flex;
    gap: 6px;
}

/* ═══════════════════════════════════════════════════
   Dialogs
   ═══════════════════════════════════════════════════ */
.dialog {
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius);
    background: var(--panel-bg);
    color: var(--panel-text);
    padding: 0;
    max-width: 380px;
    width: 90vw;
    box-shadow: 0 8px 32px rgba(0,0,0,0.6);
}

.dialog::backdrop {
    background: rgba(0,0,0,0.7);
}

.dialog h2 {
    padding: 16px 20px 8px;
    font-size: 1.1rem;
    color: var(--accent);
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

.dialog-form {
    padding: 16px 20px;
}

.dialog-form .form-group {
    margin-bottom: 12px;
}

.dialog-form .form-group:last-child {
    margin-bottom: 0;
}

.dialog-form label {
    display: block;
    font-size: 0.8rem;
    color: rgba(255,255,255,0.6);
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.dialog-form .form-select {
    width: 100%;
}

.dialog-actions {
    display: flex;
    gap: 8px;
    padding: 12px 20px 16px;
    justify-content: flex-end;
}

.dialog-btn {
    padding: 8px 20px;
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: var(--radius);
    color: var(--panel-text);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition);
}

.dialog-btn:hover {
    background: rgba(255,255,255,0.2);
}

.dialog-btn.primary {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--panel-bg);
    font-weight: 600;
}

.dialog-btn.primary:hover {
    background: var(--accent-hover);
}

#gameover-result {
    padding: 16px 20px;
    font-size: 1rem;
    text-align: center;
}

/* ═══════════════════════════════════════════════════
   Toast Notifications
   ═══════════════════════════════════════════════════ */
.toast {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    padding: 10px 24px;
    background: rgba(43, 26, 14, 0.95);
    border: 1px solid var(--accent);
    border-radius: var(--radius);
    color: var(--accent);
    font-size: 0.9rem;
    z-index: 2000;
    transition: opacity 0.3s ease;
    box-shadow: var(--shadow);
    pointer-events: none;
}

.toast.hidden { opacity: 0; }

/* ═══════════════════════════════════════════════════
   Theme Classes
   ═══════════════════════════════════════════════════ */
.theme-green .grid-cell.light { background-color: #FFFFFA; }
.theme-green .grid-cell.dark { background-color: #869E86; }
.theme-green .grid-cell.off-board.light,
.theme-green .grid-cell.off-board.dark {
    background-color: #333F33 !important;
}

.theme-brown .grid-cell.light { background-color: #f0d9b5; }
.theme-brown .grid-cell.dark { background-color: #b58863; }
.theme-brown .grid-cell.off-board.light,
.theme-brown .grid-cell.off-board.dark {
    background-color: #3E2C1E !important;
}

.theme-blue .grid-cell.light { background-color: #CCCFD1; }
.theme-blue .grid-cell.dark { background-color: #688DBC; }
.theme-blue .grid-cell.off-board.light,
.theme-blue .grid-cell.off-board.dark {
    background-color: #232F3F !important;
}

.theme-oriental .grid-cell.light { background-color: #EFEFEF; }
.theme-oriental .grid-cell.dark { background-color: #888888; }
.theme-oriental .grid-cell.off-board.light,
.theme-oriental .grid-cell.off-board.dark {
    background-color: #1F281F !important;
}

/* ═══════════════════════════════════════════════════
   Flip animation
   ═══════════════════════════════════════════════════ */
.board { transition: transform 0.4s ease; }

/* ═══════════════════════════════════════════════════
   Scrollbar styling
   ═══════════════════════════════════════════════════ */
.move-list::-webkit-scrollbar,
.console-textarea::-webkit-scrollbar,
.tab-content::-webkit-scrollbar {
    width: 4px;
}

.move-list::-webkit-scrollbar-track,
.tab-content::-webkit-scrollbar-track {
    background: transparent;
}

.move-list::-webkit-scrollbar-thumb,
.tab-content::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.15);
    border-radius: 2px;
}

/* ═══════════════════════════════════════════════════
   Responsive — Mobile
   ═══════════════════════════════════════════════════ */
@media (max-width: 768px) {
    #app {
        flex-direction: column;
    }

    #board-area {
        flex: 0 0 100vw;
        height: 100vw;
        padding: 0;
    }

    .board {
        max-width: 100vw;
    }

    #side-panel {
        flex: 1 1 auto;
        min-width: 0;
        max-width: 100%;
        min-height: 0;
        width: 100%;
    }

    .panel-header {
        padding: 10px 8px;
    }

    .move-list {
        max-height: 30vh;
    }
}

@media (max-width: 480px) {
    .board {
        border-width: 2px;
    }

    .action-btn {
        padding: 8px 4px;
        font-size: 0.75rem;
    }

    .tab-btn {
        padding: 8px 4px;
        font-size: 0.75rem;
    }
}

/* ═══════════════════════════════════════════════════
   Print styles (minimal)
   ═══════════════════════════════════════════════════ */
@media print {
    #side-panel, .toast { display: none !important; }
    #app { flex-direction: column; }
    body { background: white; }
}